Stern angle control for outboard motors



Nov. 9, 1965 P. F. THOENE STERN ANGLE CONTROL FOR OUTBOARD MOTORS 2 sheeizszsheei. -1

Filed Sept. 11, 1964 Nov. 9, 1965 oENg 3,216,393

STERN ANGLE CONTROL FOR OUTBOARD MOTORS Filed Sept. 11, 1964 2 Sheets-Sheet 2 FIG. 3. 45

' 3/ I I 5- 45 47 2 27 5 37- Z3 2g FYI FIG. 6.

United States Patent Ofi 3,215,393 Patented Nov. 9, 1965 ice 3,216,393 STERN ANGLE CONTROL FOR OUTBOARD MOTORS Paul F. Thoene, 4720 Rosa, St. Louis, Mo. Filed Sept. 11, 1964, Ser. No. 397,668 8 (Ilaims. (Cl. 11541) This invention relates to stem angle controls for outboard motors, and more particularly to a control of this class operable from within the boat while the boat is in motion to vary the stern angle of the outboard motor in accordance with the attitude of the boat.

It will be understood that in the propulsion of a boat by means of an outboard motor, it is desirable for best performance that the axis of the propeller be maintained substantially horizontal whatever the attitude of the boat may be. This means that the motor should be maintained substantially vertical whatever the attitude of the boat may be. Thus, as the speed of the boat is increased and the angle of the longitudinal axis of the boat to the surface of the water increases (i.e., as the attitude of the boat changes to a planing attitude), the stern angle (the angle between the drive shaft of the motor and the transom of the boat) must be increased to maintain the motor substantially vertical.

Accordingly, among the several objects of this invention may be noted the provision of an improved relatively low-cost control operable from within the boat while the boat is under way to change the stern angle of the outboard motor according to the attitude of the boat; the provision of a control of this class which utilizes the thrust tending to swing the motor away from the transom while the boat is under way when the motor is decelerated to accomplish outward swing of the motor, and which then utilizes the forward thrust of the propeller upon acceleration of the motor to bring the motor to a desired stern angle; the provision of a control such as described including means for automatically latching the motor at a desired stern angle, this latching means also being remotely controlled from within the boat; and the provision of a control such as described adapted for latching the motor in any of a plurality of different stern angle positions to provide increased speed of the boat when loaded and improved economy of operation of the motor as well as enhanced control of the boat. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated;

FIG. 1 is a side elevation of an outboard motor mounted on the transom of a boat by means including a stern angle control of this invention, the motor being shown in a minimum stern angle position;

FIG. 2 is a view similar to FIG. 1 showing the motor at a greater stern angle position;

FIG. 3 is an enlarged horizontal section taken on line 33 of FIG. 1;

FIG. 4 is an enlarged fragment of FIG. 3 with parts further broken away and shown in section;

FIG. 5 is a fragment of FIG. 3 illustrating parts in a position corresponding to FIG. 2;

FIG. 6 is a vertical section taken on line 66 of FIG. 5, and illustrating in dot-dash lines certain moved position of parts; and

FIG. 7 is a wiring diagram.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, there is indicated at 1 in FIGS. 1 and 2 a boat having an outboard motor 3 mounted on its transom 5 for swinging movement on a transverse horizontal axis so that the stern angle of the motor may be varied, also for swinging movement on a generally vertical axis for steering purposes. The motor 3 is conventional, comprising the usual 'drive shaft housing 7 at the upper end of which is an engine (not shown) enclosed in an engine housing 9. The propeller of the outboard motor is indicated at 11, and it will be understood that this is driven from the engine via a drive shaft 13 (see FIG. 3) extending down from the engine through the drive shaft housing 7.

The drive shaft housing 7 is pivotally mounted by means of a king pin 15 one swivel bracket 17 for swinging movement on a generally vertical axis, whereby the outboard motor as a whole is swingable on this axis for steering purposes. Swivel bracket 17 is pivotally mounted by means of a pin 19 on a transom bracket 21 for swinging movement 011 a transverse horizontal axis, whereby the outboard motor as a whole is swingable on this horizontal axis for varying the stern angle of the motor. Transom bracket 21, as will be understood, is clamped on the transom 5 of the boat.

The transom bracket 21 is provided with a pair of transversely spaced arms 23, which may be curved as illustrated in FIGS. 1, 2 and 5, and which straddle the swivel bracket 17. Extending between the arms 23 adjacent the transom bracket 21 is a pin 25 received in holes H1 in the arms. This pin is shown as having an end portion 27 bent at right angles to the length of the pin and a cotter pin 29 received in a hole at its other end to hold it in assembly with arms 23. The forward side of the swivel bracket 17 is engageable with this pin (see FIG. 3) to determine a minimum stern angle of the outboard motor (see FIG. 1) in which the motor is generally vertical when the boat is level. Arms such as indicated at 23 are conventionally provided on a transom bracket, and are conventionally provided with a series of six holes as indicated at Hl-H6. The holes H1 are those nearest the transom. The swivel bracket 17 may have a transverse notch 30 in its forward side receiving pin 25.

In accordance with this invention, each arm 23 has a solenoid housing 31 secured on the outside thereof. Each housing contains two solenoids 33 and 35 located side-byside along the length of the arm. Solenoid 33 includes a coil 37 and a plunger 39. Solenoid 35 includes a coil 41 and a plunger 43. Plunger 39 has an extension 45 constituting a first latch slidable through hole H5. Plunger 43 has an extension 47 constituting a second latch slidable through hole H4. Each latch is biased to slide inward through its respective hole by a spring 49. When the swivel bracket 17 is in engagement with stop pin 25, the ends of the latches 45 and 47 engage the sides of the bracket 17 and the latches are thereby held in a retracted position as illustrated in FIGS. 3 and 4 against the bias of springs 49. Also, the latches 45 and 47 are movable to retracted position upon energization of the respective solenoid coils. Holes H6 and H3 in each arm are utilized for the reception of means for fastening the respective solenoid housing 31 to the arm. Each fastening means comprises an expansible plug 51 received in the respective hole and a screw 53 which is threaded in a tapped hole 55 in the housing 31 and which expands the plug to secure it in the respective hole H6 or H3. Hole H2 is not utilized.

Referring to FIG. 7, the solenoid coils 37 for the aft pair of latches 45 are shown to be connected in parallel circuits 57 and 59 to ground energized via a line 61 including a switch 63 from the positive terminal of a battery B (which may be the battery for the outboard motor). The solenoid coils 41 for the forward pair of latches 47 are shown to be connected in parallel circuits 67 and 69 to ground energized via a line 71 including a switch 73 also connected to the positive terminal of the battery B. The arrangement is such that whenever switch 63 is closed coils 37 are energized; and whenever switch 73 is closed coils 41 are energized.

FIG. 1 shows the boat 1 in a substantially level attitude, and the outboard motor 3 in a minimum stern angle position determined by the engagement of the swivel bracket 17 with the stop pin 25, which constitutes a fixed stop (see FIG. 3). The stern angle is then such that the axis of the propeller 11 is substantially horizontal. It will be understood that the boat will remain in a level attitude such as illustrated in FIG. 1 at low speeds. However, when the speed of the boat is increased, the boat will assume a planing attitude such as illustrated in FIG. 2. If the stern angle were to remain the same, the axis of the propeller would then become inclined. However, the stern angle control of this invention enables the stern angle to be easily changed from within the boat as follows:

The operator of the boat, by momentarily cutting the throttle of the outboard motor 3, reduces the thrust of the propeller 11. With the boat under way, this causes the motor 3, together with the swivel bracket 17, to swing away from the transom 5. Initially, the latches 45 and 47 are held in the retracted position illustrated in FIGS. 3 and 4 by engagement of their inner ends with the sides of the swivel bracket 17. As the motor 3 and the swivel bracket 17 swing away from the transom, both pairs of latches 45 and 47 move inward to the position illustrated in FIG. 5 under the bias of springs 49. In this position, the aft pair of latches 45 is engageable by the forward side of the swivel bracket 17. Then by increasing the throttle setting to increase the thrust of the propeller 11, the motor 3 and the swivel bracket 17 are made to swing down to a position determined by engagement of the forward side of the swivel bracket with the aft pair of latches 45, as illustrated in FIG. 5 and as illustrated by the line X in FIG. 6. This determines a greater stern angle between the motor and the transom 5 as will be apparent from FIG. 2. If this angle is too high, the operator may, by momentarily cutting the throttle and closing the switch 63, actuate the coils 37 for the aft pair of latches 45 to retract them, and then by increasing the throttle setting cause the motor 3 and swivel bracket 17 to swing further toward the transom to a position determined by engagement of the forward side of the swivel bracket with the forward pair of latches 47, this position being illustrated by the line Y in FIG. 6. This determines an intermediate stern angle position of the motor 3. When the speed of the boat is reduced to the point where it again assumes a level attitude, the operator may, by momentarily cutting the throttle and closing the switch 73, retract the forward pair of latches 47; and then by increasing the throttle setting make the motor 3 swing toward the transom 5 to its minimum stern angle position determined by engagement of the forward side of the swivel bracket 17 with the fixed stop pin 25.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A stern angle control for an outboard motor carried by a swivel bracket which is pivotally mounted for swinging movement on a transverse horizontal axis on a transom bracket clamped on the transom of a boat, said transom bracket having a pair of arms extending aft therefrom straddling the swivel bracket and having a fixed stop extending between said arms engageable by said swivel bracket for determining a minimum stern angle position of the motor, said swivel bracket with the motor thereon being swingable away from said minimum stern angle position when the boat is under way upon reduction in the thrust of the motor, said control comprising latch means on at least one of said arms located aft of said fixed stop and normally held in a retracted position by engagement with said swivel bracket when the latter is in said minimum stern angle position and automatically movable into a latching position in the path of said swivel bracket when the latter swings beyond said latch means for engagement of said latch means by said swivel bracket upon downward swing of the latter to determine a position of the motor at a greater stern angle, and means operable from within the boat to retract said latch means to allow the motor to swing toward its minimum stern angle position.

2. A stern angle control as set forth in claim 1 wherein said latch means is spring-biased toward latching position, and wherein said retracting means comprises electrical means for retracting said latch means against the spring bias.

3. A stern angle control as set forth in claim 2 wherein said retracting means comprises solenoid means connected in a circuit including switch means in the boat.

4. A stern angle control as set forth in claim 1 wherein said latch means comprises a lurality of latches adapted to latch the motor in a plurality of different stern angle positions.

5. A stern angle control as set forth in claim 4 wherein each latch is spring-biased toward latching position, and wherein said retracting means comprises an electrical means for each latch each adapted to retract the respective latch against the spring bias.

6. A stern angle control as set forth in claim 5 wherein each electrical means comprises a solenoid each connected in a circuit including a switch in the boat.

7. A stern angle control for an outboard motor carried by a swivel bracket which is pivotally mounted for swinging movement on a transverse horizontal axis on a transom bracket clamped on the transom of a boat, said transom bracket having a pair of arms extending aft therefrom straddling the swivel bracket, each arm having a series of lateral holes therein spaced at intervals along its length, and a pin extending between said arms received in a first pair of said holes and engageable by the forward side of the swivel bracket for determining a minimum stern angle position of the bracket, a solenoid housing mounted on the outside of each arm by means of fasteners received in others of the holes in the arm, each housing containing a solenoid coil and plunger with an extension from the plunger slidable in another of said holes and constituting a latch, springs for biasing the latches inward, said latches being held out in a retracted position by engagement of their inner ends with the sides of the swivel bracket when the latter is in said minimum stern angle position, and moving inward to a position for engagement by the forward side of the swivel bracket when the latter swings upward beyond said latches, said coils being energizable to retract said latches under control of a switch in the boat.

8. A stern angle control for an outboard motor carried by a swivel bracket which is pivotally mounted for swinging movement on a transverse horizontal axis on a transom bracket clamped on the transom of a boat, said transom bracket having a pair of arms extending aft therefrom straddling the swivel bracket, each arm having a series of lateral holes therein spaced at intervals along its length, and a pin extending between said arms received in a first pair of said holes and engageable by the forward side of the swivel bracket for determining a minimum stern angle position of the bracket, a solenoid housing mounted on the outside of each arm by means of fasteners received in others of the holes in the arm, each housing containing a plurality of solenoid coils and plungers with extensions from the plungers slidable in others of said holes and constituting latches, springs for biasing the latches inward, said latches being held out in a retracted position by engagement of their inner ends with the sides of the swivel bracket when the latter is in said minimum stern angle position, and moving inward to a position for engagement by the forward side of the swivel bracket when the latter swings upward beyond said References Cited by the Examiner UNITED STATES PATENTS 9/59 Harrison 11517 4/63 Leipert 115-41 X MILTON BUCHLER, Primary Examiner.

ANDREW H. FARRELL, Examiner 

1. A STERN ANGLE CONTROL FOR AN OUTBOARD MOTOR CARRIED BY A SWIVEL BRACKET WHICH IS PIVOTALLY MOUNTED FOR SWINGING MOVEMENT ON A TRANSVERSE HORIZONTAL AXIS ON A TRANSOM BRACKET CLAMPED ON THE TRANSOM OF A BOAT, SAID TRANSOM BRACKET HAVING A PAIR OF ARMS EXTENDING AFT THEREFROM STRADDLING THE SWIVEL BRACKET AND HAVING A FIXED STOP EXTENDING BETWEEN SAID ARMS ENGAGEABLE BY SAID SWIVEL BRACKET FOR DETERMINING A MINIMUM STERN ANGLE POSITION OF THE MOTOR, SAID SWIVEL BRACKET WITH THE MOTOR THEREON BEING SWINGABLE AWAY FROM SAID MINIMUM STERN ANGLE POSITION WHEN THE BOAT IS UNDER WAY UPON REDUCTION IN THE THRUST OF THE MOTOR, SAID CONTROL COMPRISING LATCH MEANS ON AT LEAST ONE OF SAID ARMS LOCATED AFT OF SAID FIXED STOP AND NORMALLY HELD IN A RETRACTED POSITION BY ENGAGEMENT WITH SAID SWIVEL BRACKET WHEN THE LATTER IS 